"Service Engine Light Soon" appears on dash

The Buick Century has about 22,000 miles. The Service Engine Soon light has appeared on the dash. The instruction manual is not clear. What would you recoomend? What might cause the light to appear?

The engine management system has detected a problem with the emission control system.

Some parts stores will connect a code reader to the vehicle for free to determine what code(s) are stored that’s causing the Service Engine Soon light to come on.


Do as Tester says.

Also, make sure your gas cap is on tightly. A loose gas cap can sometimes cause the light to come on.

Did you try your owners manual??

If it is still under warrantee, then just take it to the dealership and let them figure it out.

The vehicle is a 2005. So it falls out of the 8 year/80,000 mile warranty for the catalytic converter(s)and computer(s). All other emission components are only warranted for 2 years/24,000 miles.

So the dealer isn’t going do this for free.


I missed the part about it being a 2005, still don’t see it.

2005 means it was built in 2004. On the door sticker. Over the eight year period.

All other emission components are warranted for two years/24,000 miles.

See it yet?


Oh I see it now, this is the guy who wanted to epoxy his brake lines. I think we have been trolled.

Perhaps somebody should point out to OP that the epoxy might plug the hole in the brake line so well, that it actually prevents brake fluid from reaching the brake caliper


I could not resist making that comment . . .

GM declared bankruptcy in 2007…Perhaps the 2005 Buick was part of the problem…You can only sell POS cars for so long and stay in business…The “NEW” GM seems to be doing MUCH better…The 2014 Impala seems to be a world-beater…We shall see…

I still don’t see anything that identifies it as a 2005, and what makes you think it was built in 2004, not all 2005s were. For warranty purposes it is the "in service date’ that counts.

I agree with @oldtimer11

You could have a 2005 car that was built in June of 2005 . . .

All the owner needs to do is open the drivers door, and lookat the placard that reflects when the vehicle was manufactured. I bet it say’s 2004.


2005 cars could have been built from 8/2004 to 7/2005. But when it was built doesn’t really matter for warranty concerns. The dealer will look up the vin and use the in-service date (the date the car was first sold) and start the warranty timer from there.

Since it is now 2013, the inservice date is a moot point. Why are we have an argument over a post by someone who appears to be a troll?